The present invention relates to an implant device.
There are many situations in which it is necessary to perform an enterostomy on a patient. An enteroostomy involves externalizing an internal vessel. Common vessels which commonly require externalizing are the ileum, colon, ureter, and bladder. Heretofore, enterostomies were accomplished by severing the vessel which was to be externalized and then suturing the wall of the vessel to an opening which has been formed on the surface of the body. The opening is normally formed on the abdomen. Generally, the wall of the vessel and the dermis of the skin surrounding the opening will grow together to permanently secure the vessel to the surface of the body. After the operation has healed, a container is attached to the surface of the skin. The container functions to receive the excrements which are discharged from the vessel. These excrements may be acidic due to the pressure of enzymes et cetera, and when they contact the surface of the skin, they cause ulceration. For example, in an ileostomy, the ileum is externalized to the abdomen of the patient and the enzymes, fecal material, et cetera, which exit from the ileum cause ulceration of the skin surrounding the point of externalization. This is primarily due to the presence of active enzymes in the small intestines.
Further, there are a number of situations in which it is necessary to provide for fluid communication with the vascular system. For example, patients suffering from kidney failure require the dialysis of their blood by means external from the body. Blood containing toxic substances, such as urea, uric acid, creatine, phosphorous and calcium, must be removed from the blood system, treated and then returned to the patient. Patients requiring such blood dialysis require treatment at least two or three times per week. Patients suffering from hypoalimentation require a device for providing access to the body's vascular system on at least a daily basis.
One prior method of providing fluid communication with the vascular system involved the insertion of a needle into an artery from which blood to be treated was taken and the insertion of a needle into a patient's vein for blood return. Such a method proved unsatisfactory due to the difficulty in providing for the healing of the artery upon removal of the needle and the trauma produced by the repeated needle insertions. Such shortcomings led to the development of external and, later internal shunts.
An external shunt involves the insertion of the tubes, such as those made of Teflon, into an artery and an adjacent vein in a limb and providing an external communication or shunt between the tubes, which extend from the body of the patient. The shunt between the tubes is required in order to provide flow through the tubes during that period of time that access is not required for blood treatment. Where such circulating blood flow not provided, a blood clot or thrombus could form as would be the case if the tubes were simply capped creating a static blood volume when the tubes were not in use. Dialysis, for example, is accomplished by connecting the arterial and venous tubing to a suitable dialysis unit. However, such a configuration traumatizes the skin adjacent the Teflon tubes and a path is provided through the skin for infection to enter the patient's body. Furthermore, even with external shunts, blood clots sometimes form within the tubes and create a health hazard to the patient.
The disadvantages of external shunts led to the development of the internal shunt. An internal shunt is performed by joining, within a body, openings between an artery and an adjacent vein, thereby forming a fistula. One or two needles were then inserted into the fistula in order to achieve communication with the patient's vascular system. The patient suffers major discomfort and pain each time the needles are inserted in the fistula. Moreover, the continous intrusion into the fistula causes it to become layered with scar tissue which ultimately prevents further intrusion, thus requiring the formation of another shunt.
Both the internal and external shunts increase the loading on the patient's heart due to the joining of the artery to a vein having a lower pressure, thereby lowering the artery's pressure, and requiring the heart to attempt to regain the original arterial blood pressure. Further, in many cases, the reduced circulation in the distal portion of the limb wherein the shunt is effected impairs the adequate perfusion of blood.